Hoisting and launching apparatus for dinghy



Dec. 31-, 1968 P. T. MAROTTA 3,418,671

HOISTING AND LAUNCHING APPARATUS FOR DINGHY Filed March 6, 1967 INVENTOR QM WK.

ATTORNEYS.

United States Patent 3,418,671 HOISTING AND LAUN CHIN G APPARATUS FOR DINGHY Patrick T. Marotta, Rockaway Valley Road, Boonton Township, NJ. 07005 Filed Mar. 6, 1967, Ser. No. 620,870 18 Claims. (Cl. 939) ABSTRACT OF THE DISCLOSURE The disclosure relates to apparatus for handling a dinghy which is carried aboard a ship. A davit structure swings angularly about a horizontal fore-and-aft axis on pivot connections to a frame which is itself movable athwartship along tracks attached to the deck of the ship. Flexible cables passing over pulleys on the davit structure pull the dinghy up into contact with the davit structure as the cables are wound on a winch while the davit structure is in outboard position. Continued winding of the cables pulls the davit structure upward and inward about the pivot connections to turn the dinghy into a position bottomside up over the deck. The frame then moves further inboard along the tracks to carry the dinghy to its final inboard location. Motor means have automatic controls for the sequence of operations.

Brief description of the invention This invention has a davit structure that swings about a fore-and-aft axis from an outboard position in which the dinghy structure extends over the water alongside a ship to an inboard position in which the davit structure overlies a deck of the ship.

The term deck is used in a generic sense to include part of a ship on which people walk and also to include cabin tops which are not intended for walking on. One of the advantages of the invention is in hoisting a dinghy from the water and loading it on top of a cabin roof of a medium-sized cruiser where there are no railings and it is difiicult to stand for operating conventional davits, especially when the water is rough and the cruiser is rolling. The apparatus of this invention lends itself to automatic operation by motor means and the preferred embodiment of the invention has motor means.

In the preferred embodiment, the dinghy is hoisted from the water by flexible cables passing over guides or pulleys on the davit structure, and when the dinghy has been pulled up into contact with the davit structure, continued winding of the cables pulls the davit structure upward and inward toward its inboard position. Stops against the gunwale of the dinghy hold the dinghy in place on the davit structure during this movement; and after the davit structure has swung beyond a substantially vertical position, it contacts with a guide arm that controls the rate at which the davit structure and the dinghy come down by gravity to their positions overlying the deck.

The same guide arm is used to raise the davit structure and the dinghyto a position from which they can move by gravity into their outboard position, and the unwinding of the cables is controlled to retard the rate of descent of the davit structure and the dinghy as they move out board and downward.

Other features of the invention relate to the correlation of motor means and controls for regulating the sequence of operations for both loading and unloading the dinghy, including limit switch means that control the power supply to the motor means.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

3,418,671 Patented Dec. 31, 1968 Brief description 0 the drawing In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views:

FIGURE 1 is an isometric view showing the dinghyhandling apparatus of this invention with the davit structure in its outboard position and the dinghy part way toward the water;

FIGURE 2 is an end view of the structure shown in FIGURE 1 with the parts in different positions to illustrate the sequence of operation;

FIGURE 3 is a wiring diagram for the apparatus shown in the other views; and

FIGURE 4 is a sectional view taken on the line 4-4 of FIGURE 1.

Detailed description of the invention FIGURE 1 shows a portion of a cruiser including a cabin 12 extending upward from a side deck 14 along which there is a railing 16. There is a roof or deck 18 at the top of the cabin, and the apparatus of this invention is connected to the deck 18.

The invention includes rails 21 which are rigidly secured to the deck 18 and which extend far enough across the deck so as to support a dinghy in a center position on top of the cabin. The rails 21 extend close to the starboard side of the deck 18 so that the dinghy can be lowered into water from that side of the cruiser.

There is a frame 24 which has rollers 26 which run along the rails 21. This frame 24 is a carriage and includes a center section 28 connected with side structures 30 by suitable bracing 32. There are end structure 34 at both ends of the frame 24 and extending generally parallel to the rails 21.

Brackets 38 are rigidly secured to the. end structures 34 near the outboard ends of these end structures. Each of the brackets 38 support an arm 40 of a davit structure 42 that includes the arms 40 and a connecting truss 43 which is rigidly connected to the arms 40 and which forms, with the arms 40, an integral unit. This davit structure is connected with the brackets 38 by pivot connections 46 so that the davit structure can swing angularly from outboard position, as shown in FIGURE 1, to an inboard position lying generally parallel to the rails 21, as shown in dotted lines on the left-hand side of FIG- URE 2.

A dinghy 50 is supported from the arms 40 of the davit structure by flexible cables 52 which extend around guides or pulleys 54 located on the arms 40 far enough out on the arms to support the dinghy clear of the hull of the cruiser.

There are weights 56 at the lower end of each of the flexible cables 52, and a hook 58 at the bottom of each of the weights 56 engages lifting straps 60 attached to the dinghy near its opposite ends. The arms 40 are spaced fore-and-aft by a distance somewhat less than the length of the dinghy 50 so that the dinghy can be pulled up into contact with the arms, as will be explained in connection with FIGURE 2. The weights 56 are below the level of the dinghy gunwales so that the gunwales contact with the arms 40 before the weights reach the arms or pulleys 54 when the dinghy is hoisted.

The flexible cables 52 change their direction around the pulleys 54 and run inward to other pulleys 64 located at the inboard end of the frame 24. After passing around these pulleys 54, the cables 52 wind on the drum of a winch 66 which is driven by an electric motor 68 through suitable reduction gearing.

A crank can be attached to the winch drive gearing for manually lowering or raising the dinghy in the event of electrical power failure. An electric brake that holds the winch must be manually released before the crank is turned. Such manual overrides are well understood mechanical expedients and no illustration of one is necessary for a complete understanding of this invention. The winch 66 and motor 68, together with the associated reduction gearing, are rigidly secured to the frame 24 by a bracket 70 so that the winch 66 and its associated driving means travel as a unit with the frame 24 as the frame moves along the rails 21. Thus movement of the frame 24 along the rails 21 does not change the length of the cables 52 between the winch 66 and the dinghy 50.

There are blocks 72 secured to the frame 24 in position to limit the movement of the arms 40 in an outboard direction. The arms 40 are in contact with the blocks 72 in FIGURE 1. Thus when the arms 40 are in their lowermost position, the flexible cables 52 extend in a direction making a substantial acute angle to the direction of extent of the arms 40 toward their pivot connections 46. The initial winding of the cables 52 on the drum of the winch 66 lifts the dinghy 50 out of the Water, and continued winding raises the dinghy into contact with the arms 40, as shown in solid lines in FIG- URE 2.

When the cables 52 can not raise the dinghy 50 any further, the continued pull on the cables 52 causes the davit structure 42 to swing upward into the substantially vertical position shown in dotted lines in FIGURE 2. There is a stop 76 secured to each of the arms 40 in position to engage the gunwale of the dinghy 50 so that the dinghy can not slide down on the arms 40 as they swing upward about the pivot connections 46. In the preferred construction, the stops 76 are undercut so that they grip the rub rail of the dinghy and prevent the dinghy from swinging away from the arms 40 as the dinghy is swung u ward and inward.

There are other stops 80 on the arms 40 for contact with the rub rail on the other side of the dinghy from the stops 76. These other stops 80 are preferably adjustable along the arms 40 as indicated by the plurality of bolt holes 82 and the adjustability of these other stops 80 makes the apparatus suitable for use with dinghies of somewhat different beam. The principal purpose of these other stops 80 is to prevent the dinghy from shifting on the arms 40 when they are moved into their ultimate position over the deck, as shown in dotted lines at the right-hand side of FIGURE 2.

When the davit structure 42, with the dinghy on it, reaches the substantially vertical position shown in FIG- URE 2, the davit structure contacts with a guide arm 86 which has a pivot connection 88 (FIGURE 4) to a support 90 which slides along a guide 91 attached to the deck 18. This support 90 extends downward through a slot 92 in the center section 28 and a part of the support 90 is a nut 94 on a lead screw 96 within the center section 28 extending parallel to the guide 91, as shown in FIGURE 4.

There is a limit switch 100 (FIGURE 1) at the upper end of the guide arm 86; When the davit structure 42 contacts with the guide arm 86, it operates the limit switch 100 and starts a motor which rotates the lead screw 96 in a direction to move the support 90 (FIGURE 4) toward the left along the guide 91 of the frame 24. Continued movement of the support 90 toward the left causes the guide arm 86 to move clockwise about its pivot connection 88 and to let the davit structure 42 descend into a position that locates the arms 40 substantially parallel to the rails 21.

When the support 90 reaches the end of the slot 92, continued rotation of the lead screw 96 causes the entire frame 24 to advance with the nut 94 along the lead screw.

The lead screw 96 is rotated by an electric motor 104 through reduction gearing 106. The motor 104 and the reduction gearing 106 are secured to the deck 18 by a bracket 110. There is another limit switch 112 on the deck 18 in position to be operated by the frame 24 when the frame has moved as far as desired along the rails 21. Operation of this limit switch 112 stops the motor 106 and leaves the frame 24 and the davit structure 42 in the position shown in dotted lines at the left-hand side of FIGURE 2. It should be noted that the dinghy 50 is turned bottomside up over the winch 66, the motor 68, motor 104, and reduction gearing 106 so that they are protected from the weather by the dinghy.

When the dinghy is to be launched again, the motor 104 is operated in a reverse direction so that the lead screw 96 advances the nut 94 toward the right. This initial movement of the nut 94 moves the guide arm 86 into engagement with the davit structure 42, but since it is much less effort to move the frame 24, the davit structure 42 and the dinghy 50 along the rails 21, than to swing the davit structure upward with the Weight of the dinghy on the davit structure, the continued rotation of the lead screw 96 merely moves the frame 24 along the rails 21.

When the frame 24 has moved as far as desirable along the rails 21, an abutment 116, at each end of the frame 24, strikes against a stop 118 on each of the rails 21. When the lead screw can move the frame 24 no further to the right, continued movement of the nut 94 along the lead screw moves the support and causes the arm 86 to swing the davit structure 42 upward. There are springs 122 attached to the end structures 34 for imparting the initial upward swinging movement to the arms 40 of the davit structure 42. These springs lift the weight of the dinghy and davit structure at a time when the guide arm 86 has very little obliquity with respect to the davit structure 42. As the davit structure swings upward (clockwise) in FIGURE 2, the guide arm 86 swings counterclockwise about its pivot connection 88 and into a position to exert greater mechanical advantage in lifting the davit structure 42 and the dinghy 50.

Continued rotation of the lead screw 96 moves the nut 94 and the lower end of the guide arm 86 so as to swing the davit structure 42 into a substantially vertical position, as shown in dotted lines in FIGURE 2. When the guide arm 86 reaches its limit of travel along the slot 92. and contacts with a stop 126, the center of gravity of the dinghy 50 is beyond the pivot 46 and the davit structure 42 and dinghy 50 move by gravity into the full-line position shown in FIGURE 2. This movement by gravity is retarded, however, by the rate at which the flexible cables 52 unwind from the winch 66. This rate is controlled by the speed of rotation of the motor which drives the winch. Movement of the davit structure 42 away from the guide arm 86 permits the limit switch to operate so as again to supply power to the motor for the winch 66, but the rotation of the motor is in a direction to unwind the cable 52 since the circuits for the motors 104 and 68 are both reversed by a control switch when the apparatus is operated to launch the dinghy.

The arms 40 swing downward into the position shown in full lines in FIGURES 1 and further unwinding of the flexible cables 52 causes the dinghy 50 to move downward until it is in the water. The switch 130 is then operated to stop the winch motor and someone gets in the dinghy to disconnect the hooks 58 (FIGURE 1) from the hoisting straps 60; and the switch 130 can then be operated to wind the flexible cables 52 back without the din hy connected with them.

When the weights 56 reach the pulleys 54, the davit structure is swung inboard in the,same way as when the dinghy was hoisted, and this brings the davit structure into a position over the deck without the dinghy on the davit structure.

FIGURE 3 shows a wiring diagram for the apparatus shown in the other figures. The power is supplied to the motors from a battery 136 which is ordinarily the source of electric power for the cruiser. The switch 130 is preferably a three-position switch. When closed in one direction, the circuits supply power to drive the motors 68 and 104 in a direction to hoist the dinghy and move it inboard. When the switch 130 is closed in the opposite direction, the circuits are closed to supply power in a direction to reverse the motors 68 and 104 to rotate them in a direction to swing the davit structure outboard with the dinghy on it for launching, or into position over a dinghy in the water when the dinghy is to be brought aboard. In its midposition, the switch 130 opens the motor circuits.

The switch 130 is preferably connected with the other part of the electric circuit through a multi-conductor cable 140 which is preferably flexible so that the switch 130 can be connected with the end of the cable and moved about from place to place for convenient handling by a person watching the hoisting or launching of the dinghy. By having the switch 130 on the flexible cable 140, the person operating the apparatus can move about, as necessary, to watch the progress of the operation.

The operation will now be described with reference to FIGURES 1 and 3. When the dinghy has been connected with the cables and is ready to lift out of the water, the master control switch 130 is closed against its upper contacts (FIGURE 3) and current from the battery 136 flows through conductor 150, through the left blade of switch 130 and through conductor 152 to the limit switch 112 which is closed when the davit structure is in its outboard position.

The switch 112 is in series with a double throw switch 154 which is normally closed against its top contacts to continue the circuit to the motor 68 through a resistance 156. A shunt circuit, around the resistance 156, passes through the switch 100, which is normally closed against its upper contacts, to the motor '68. The other side of the motor 68 is connected with the right side of the switch 130 by conductors 158 and 159.

The motor 68 continues to run and rotate the winch 66 while the dinghy is pulled up into contact with the davit structure arms 40 and while the davit structure is swung up into contact with the guide arm 86 where the davit structure operates the switch 100 to open the circuit between its upper contacts and to close the circuit between its upper contacts and to close the circuit between its lower contacts. This breaks the shunt circuit around the resistance 156 so that the power to the winch motor 68 is reduced and the motor 68 continues to operate merely as a torque motor to wind the cables 52 as the guide arm 86 (FIGURE 1) lets the davit structure and dinghy come down by gravity on the frame 24.

The movement of switch 100 to close the circuit across its lower contacts establishes a circuit from the switch 154 through the switch 100 and conductor 162 to the motor 104 that rotates the lead screw 96. When the davit structure comes down, one of the arms 40 contacts with the switch 154 on the forward end structure 34 (FIGURE 1) and this opens the circuit between the upper contacts and closes a circuit between the lower contacts of the switch 154. This provides an automatic stop for the winch motor 68 which is cut out of the circuit since there will be no further slack cable to wind on the winch 66, but the circuit to the motor 104 is maintained through the conductor 162.

When the lead screw 96 has moved the frame 24 and the dinghy into final inboard position, the frame operates the limit switch 112 and opens the circuit of the motor 104. Thus the apparatus has an automatic stop when operated to hoist the dinghy and to position it on the deck.

When the dinghy is to be launched again, the switch 130 is operated to close it against its lower contacts. This supplies current to the motor 104, but in a reverse direction, to rotate the motor 104 and lead screw 96 in a direction to move the frame and dinghy outboard. The circuit is from the battery 136 through a conductor 166, right hand blade of switch 130 and through a conductor 168 which leads to the motor 104 through a switch 174 that is normally closed against its left hand contacts. Another conductor 176 connects the other side of the motor 104 with the master control switch 130, and the conductor leads back to the battery.

The motor 104 continues to operate until the guide arm 86 (FIGURE 4) comes against the stop 126 and operates the limit switch 174. This opens the circuit between the left hand contacts (FIGURE 3) of switch 174 and closes a circuit between the right hand contacts. This stops the motor 104. Thus the switch 174 provides an automatic stop for motor 104.

When the lead screw 96 has moved the frame and dinghy all the way to the outboard ends of the rails 21 and then starts to swing the frame and dinghy upward, the arm 40 of the davit structure rises and permits the switch 154 to return to its normal position closing the circuit through the upper contacts of this switch 154. This closes a circuit through the conductors 176 and 158, the motor 68, switch 154, and conductor 180 to conductor 168 which connects with the other side of the switch 130.

The motor 68 runs at reduced speed since the resistance 156 is in series with the motor 68. The flexible cables unwind slowly from the winch as the davit structure 42 and dinghy are swung upward. When the lead screw has moved the support 90 to the outboard end of its stroke and has thereby shifted the switch 174 to the right in FIGURE 4, a conductor (FIGURE 3) is put into the circuit between the motor 68 and the conductor 168 to by-pass the resistance 156 and to cause the motor to run at its full speed.

The davit structure 42 swings outboard restrained by the slowly unwinding cables 52 until the davit structure comes into contact with the blocks 72. Continued unwinding of the flexible cables 52 lowers the dinghy into the water. There is no automatic stop governed by contact of the dinghy with the water. The motor 68 is stopped by operating the switch 130 to open the circuits through the switch 130. The time for opening this switch 130 depends upon how much slack a person may want before unhooking the cables from the dinghy and this in turn depends upon how much the dinghy is bobbing up and down in the waves. Conventional limit switches can be provided to stop the winch before the cable is completely unwound from the winch.

What is claimed is:

1. Dinghy-handling apparatus including brackets for location on the deck of a ship, davit structure movable angularly athwartship from an inboard position overlying and substantially parallel to the deck to another position extending outboard beyond the deck for holding a dinghy over the water alongside the ship, pivotal connections between the davit structure and the brackets and about which the davit structure has said angular movement, the davit structure having arms at a predetermined fore-andaft spacing from one another less than the length of the dinghy with which they are intended to be used, and hoisting means including flexible cables that extend over guides on the davit structure and downward to a dinghy hanging by said cables from the davit structure when in its outboard position, the hoisting means including apparatus for moving the cables to bring the dinghy up against the davit structure and for swinging the davit structure into its inboard position whereby the dinghy against the davit structure is turned bottomside-up as the davit structure moves angularly into its inboard position.

2. The dinghy-handling apparatus described in claim 1 characterized by stops on the davit structure in position pivot sides of the davit structure, and other stops toward the other side of the davit structure for preventing shifting of the dinghy along the davit structure in a direction away from the first stops when the davit structure is in its inboard position overlying the deck.

4. The dinghy-handling apparatus described in claim 2 characterized by the stops on the davit structure being undercut and shaped to extend under a rub rail of the dinghy to not only prevent the dinghy from sliding down on the davit structure while being turned over, but also to hold the dinghy against the davit structure along one side of the dinghy, and cable guides on the davit structure located over the keel region of the dinghy so that the cables hold another portion of the dinghy against the davit structure.

I 5. The dinghy-handling apparatus described in claim 1 characterized by the means for hoisting the dinghy in cluding a winch that winds the cable to hoist the dinghy to the davit structure and to then swing the davit structure and the dinghy upward and inward, a guide arm that contacts with the davit structure at a location when the davit structure has moved slightly inboard from a vertical position, mechanism for moving said guide arm at a con trolled speed to retard the rate of movement of the davit structure as it swings downward into its inboard position overlying the deck.

6. The dinghy-handling apparatus described in claim 5 characterized by mechanism for moving the guide arm including a support that moves athwartship, a pivotal connection between the guide arm and said support, the guide arm having pivotal movement on the davit structure so that the guide arm serves as a link operably connecting the davit structure with said support, and means for moving the support selectively toward and from the davit structure to swing said davit structure one way or the other about its pivot connections with the brackets.

7. The dinghy-handling apparatus described in claim 6 characterized by the guide arm being movable to a location that carries the dinghy structure from an inboard position to substantially vertical position from which the davit structure with a dinghy on it will continue its movement toward outboard position by gravity, the davit structure moving clear of said guide arm as it moves beyond said substantially vertical position.

8. The dinghy-handling apparatus described in claim 7 characterized by a frame by which the brackets are carried, tracks for connection to a deck and along which the frame is movable athwartship, when the davit structure is in its inboard position, to shift the davit structure and a dinghy carried thereby farther inboard, the winch being carried on structure that travels with said frame.

9. The dinghy-handling apparatus described in claim 8 characterized by common operating mechanism for sequentially moving the support for the guide arm farther inboard and then moving the frame farther inboard after the dinghy has been hoisted up to the davit structure and the davit structure has been moved to its inboard position, the operating mechanism being reversible for moving the support and frame in reverse sequence for launching the dinghy.

10. The dinghy-handling apparatus described in claim 9 characterized by said common operating mechanism including a lead screw extending through threads in the support, and a reversible electric motor that rotates the lead screw, the support serving to move the frame or the arm, depending upon which moves with the lesser resistance at any given time.

11. The dinghy-handling apparatus described in claim 1 characterized by means for moving the davit structure from its inboard position overlying the deck to a position from which the davit structure completes its angular movement into outboard position by gravity, and means for controlling the rate of movement of the davit structure into its outboard position and to control the rate at which the dinghy is lowered, from the davit structure, into the water.

12. The dinghy-handling apparatus described in claim 11 characterized by the means for hoisting the dinghy including a winch that Winds the cables to hoist the dinghy to the davit structure and to then swing the davit structure and dinghy upward and inward, a guide arm that contacts with the davit structure at a location where the davit structure has moved slightly inboard from a vertical position, mechanism for moving said guide arm at a controlled speed to retard the rate of movement of the davit structure as it swings downward into its inboard position overlying the deck.

13. The dinghy-handling apparatus described in claim 1 characterized by a frame and means on which the frame is movable athwartship, the brackets being connected with the frame and being movable therewith, and mechanism for moving the frame in one direction after the davit structure has swung into its inboard position to move the davit structure farther inboard, said mechanism being reversible for moving the frame in the other direction before the davit structure is swung angularly into its outboard position.

14. The dinghy-handling apparatus described in claim 13 characterized by a Winch for winding the flexible cables, pulleys intermediate the opposite sides of the davit structure and around which the cables pass to change their direction of travel, a dinghy connected with the ends of the cables at locations over the keel line of the dinghy and spaced fore-and-aft by substantially the same spacing as the pulleys, the dinghy being pulled up to the davit structure by winding of the cables on the winch, the direction of the extent of the cables from the pulleys to the winch being above and at an angle to the outboard extent of the davit structure whereby continued winding of the cables on the winch, after the dinghy has been pulled up to the davit structure, swings the davit structure and the dinghy upward and inward, motor means for the winch, other motor means for the mechanism that moves the frame when the davit structure is in its inboard position and the dinghy is bottomside-up over the deck, contrcfi s including limit switches operated by movement of parts of the apparatus for controlling the supply of power lo the motor means, a flexible cable extending to a point remote from the motor means, and a manual control switch at the end of the cable including a reverse switch for the power supply to the motor means, said motor means being located under the dinghy when the dinghy is in its most inboard position.

15. The dinghy-handling apparatus described in claim 1 characterized by the hoisting means including an electric motor, and an automatic stop for the motor responsive to movement of the davit structure to its inboard position.

16. The dinghy-handling apparatus described in claim 1 characterized by the hoisting means including power means for winding the flexible cables, a frame by which the brackets are carried and by which the davit structure and the dinghy are moved further inboard on the deck in addition to the swing movement of the davit structure, other power means for moving the frame athwarthship, and automatic control means for operating the power means in a predetermined sequence.

17. The dinghy-handling apparatus described in claim 1 characterized by the hoisting means including power means for winding the flexible cables, a frame by which the brackets are carried and by which the davit structure and the dinghy are moved further inboard on the deck in addition to the swinging movement of the davit structure, other power means for moving the frame athwarthship, the power means including electric motor means, a control switch for the electric motor means, the control switch being on the end of a flexible cable and being portable for movement into difi'erent positions from which a person operating the control switch can Watch the dinghy as it is moved by the operation of the dinghy-handling apparatus.

18. The dinghy-handling apparatus described in claim 17 characterized by motor means including two electric motors, one for Winding the cables and the other for moving the frame, and automatic means responsive to movement of parts of the apparatus for determining the sequence of operation of the electric motors.

References Cited UNITED STATES PATENTS MILTON BUCHLER, Primary Examiner.

T. W. BUCKMAN, Assistant Examiner.

US. Cl. X.R. 

